Anti-nuclear factor I B antibodies are used for the immunodetection of the protein encoded by the NFIB gene. In humans, the canonical protein has a reported length of 420 amino acid residues and a mass of 47.4 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 6 different isoforms for this protein. A member of the CTF/NF-I protein family, it is reported to be a transcriptional activator of GFAP, essential for proper brain development. The gene encoding this protein is implicated in Macrocephaly. Other names for this target antigen include HMGIC/NFIB, MACID, NF1-B, NFI-RED, NFIB2, NFIB3, nuclear factor 1 B-type, and CTF. Gene orthologs have been identified in the mouse, rat, bovine, frog, chimpanzee and chicken species. Over 80 citations in the literature describe the use of nuclear factor I B antibodies in research. Western Blot is a widely used application for these antibodies. In addition, Immunohistochemistry is also a common application.